Many animals are surface-bounded, traveling mostly in two-dimensional (2D) environments. However, those that inhabit structured habitats might also require wayfinding in three-dimensional (3D) environments. Here we forced rodents to ascend or descend when traveling. We tested three species: laboratory rats (a common experimental subject); fat sand rats, which forage while climbing shrubs (representing those used to 3D travel); and Tristram's jirds, which forage in plains (not used to climbing). We examined differences between individuals initially placed on top of the apparatus compared with those placed on its bottom, assuming that this, in addition to the above difference in habitats and motor habits, would influence their spatial behavior. Exploratory activity of top-starting rats and sand rats, but not jirds, differed from bottom starters. Nevertheless, despite the need to continuously ascend or descend, both top- and bottom-starters of the three species displayed the spatio-temporal structure of open-field exploration as previously revealed in a horizontal arena. Specifically, exploration constituted a set of round-trips to a home-base. It is suggested that the preservation of a regular structure of spatial behavior was due to the ability of the tested rodents to mostly maintain a horizontal posture of their head when ascending and descending.

中文翻译：

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啮齿动物如何探索三维环境？栖息地相关和方向相关的差异

许多动物都是有界的，主要在二维 (2D) 环境中旅行。然而，那些居住在结构化栖息地的生物可能还需要在三维 (3D) 环境中进行寻路。在这里，我们强迫啮齿动物在旅行时上升或下降。我们测试了三个物种：实验室大鼠（常见的实验对象）；肥沙鼠，在攀爬灌木时觅食（代表那些习惯于 3D 旅行的老鼠）；和崔斯特瑞姆的 jirds，它们在平原上觅食（不习惯攀爬）。我们检查了最初放置在装置顶部的个体与放置在其底部的个体之间的差异，假设除了上述栖息地和运动习惯的差异外，还会影响他们的空间行为。最上层的老鼠和沙鼠的探索性活动与最底层的老鼠不同，但 jirds 不一样。尽管如此，尽管需要不断上升或下降，三个物种的顶部和底部启动器都显示出先前在水平舞台上显示的开放领域探索的时空结构。具体来说，探索构成了一系列到基地的往返。这表明空间行为的规则结构的保留是由于被测试的啮齿动物在上升和下降时大部分保持头部水平姿势的能力。